CAROTENOID PIGMENTS IN MALE HOUSE FINCH PLUMAGE IN RELATION TO AGE, SUBSPECIES, AND ORNAMENTAL COLORATION

Abstract

Abstract Like males of many bird species, male House Finches (Carpodacus mexicanus) have patches of feathers with ornamental coloration that are due to carotenoid pigments. Within populations, male House Finches vary in expression of ornamental coloration from pale yellow to bright red, which previous research suggested was the result of variation in types and amounts of carotenoid pigments deposited in feathers. Here we used improved analytical techniques to describe types and amounts of carotenoid pigments present in that plumage. We then used those data to make comparisons of carotenoid composition of feathers of male House Finches at three levels: among individual males with different plumage hue and saturation, between age groups of males from the same population, and between males from two subspecies that differ in extent of ventral carotenoid pigmentation (patch size): large-patched C. m. frontalis from coastal California and small-patched C. m. griscomi from Guerrero, Mexico. In all age groups and...